Coil tongs



Nov. 22, 1966 w. H. GALLAPOO COIL TONGS 2 Sheets-Sheet 1 Filed Feb. 9,1965 Illl/ INVENTOR.

Nov. 22, 1966 w. H. GALLAPOO 3,287,057

COIL 'IONGS Filed Feb. 9, 1965 2 Sheets-Sheet 2 INVENTOR. Warren H.aflapoa BY 637W United States Patent Office 3,287,057 Patented Nov. 2 2,1966 3,287,057 COIL TONGS Warren H. Gallapoo, Jackson, Mich., assignorto The Dow Chemical Company, Midland, Mich., a corporation of DelawareFiled Feb. 9, 1965, Ser. No. 431,370 3 Claims. (Cl. 294-81) Thisinvention relates to improved coil tongs, and particularly to fourpoint, low headroom coil tongs The lifting of coils of sheet metalpresents at least two problems. One is involved with achieving a widerange of jaw openings for the tongs without requiring a large amount ofheadroom being needed for the operation of the tongs.

Another problem is that of damaging of the coil during lifting of thecoil by the tongs. Coils are damaged be cause of unequal or excessivepressure exerted on the coil by one or more of the jaws of the tongs.

Accordingly, a principal object of this invention is to provide improvedfour point coil tongs.

Another object of this invention is to provide improved four point coiltongs which do not require an excessive amount of headroom foroperation.

A further object of this invention is to provide improved four pointcoil tongs in which pressure applied to the coil is substantiallyequalized among the four jaws of the tongs.

In accordance with this invention there is provided four point lowheadroom coil tongs using a non-powered linkage mechanism in conjunctionwith -a combination rack and pinion mechanism to achieve equal loadingof the four jaws of the tongs. As the linkage is raised, each of thepinions which are coupled to a pair of jaws through racks are rotated,causing the racks, which are each free to move, to move until resistanceis encountered by contact with a surface of the coil to be lifted. Onmeeting resistance by one rack, the pinion rotates, moving along the onerack and moving the rack which controls the other jaw of its pair ofjaws. When both jaws meet equal resistance, rotation of the pinionproduces no relative movement, but tightens both jaws of the pairequally.

The invention, as well as additional objects and advantages thereof,will best be understood when the following detailed description is readin connection with the accompanying drawing, in which:

FIG. I is a side elevational view, with part of the mechanism shown inbroken lines, of coil tong apparatus in accordance with this invention;

FIG. 2 is a side elevational view of the coil tong apparatus of FIG. 1shown with jaws engaging a coil, and

FIG. 3 is a sectional view taken along the line 33 of FIG. 1.

Referring, to the drawings, and particularly to FIGS. 1 and 3, there isshown coil tong apparatus, indicated generally by the numeral 10, havinga box-like frame indicated generally by the numeral 12, which has a topplate 14, bottom plate 16 and side plates 18, 20.

Each of the side plates 18, 20 has -a plurality of slots 22, 24, 26, 28,30, 32, 34, 36 extending through it. The slots 22, 24, 26, 28 aredisposed in line near the bottom of the side plate (20 in FIG. 1). Thepair of slots 22, 24 are on the left side of the plate, and the pair ofslots 26, 28 are on the right side of the plate. These slots 22-28 areused as a race way for rollers 38, 40 and 42, 44 for the L-shaped jawassemblies 46, 48, respectively.

In the jaw assemblies 46, 48 the part 50, '52 corresponding to the baseof the L has a jaw element 54 or 56 attached to it, the jaw facing inthe direction of the up-right member 58 or 60 of the jaw assembly.

Each of the members 58, 60 of the jaw assemblies has a pair of rollers38, 40 and 42, 44, respectively, coupled thereto with the rollers beingin the race way slots 22, 24, 26 and 28, respectively, as previouslymentioned.

Rack gear elements 62 and 64 are fixedly secured to the upwardly facingsides of the members 58 and 60, respectively. The rack gear elements 62,64 are of such length and are so disposed that at least a part of theelement lies under the slot 30 (or 32) at all times during the operationof the tongs.

Another pair of jaw assemblies 66 and 68, respectively, which aregenerally L shaped when viewed in side elevation, are disposed withtheir base parts 70 and 72, respectively, extending downwardly and theirleg parts 74, 76 lie just below the top plate 14 within the frame 12.

Roller assemblies 78 or 80 are coupled to each of the parts 74, 76 andride in the race way slots 34, 36 as do the rollers 38, 40, 42 and 44 inslots 22, 24, 26, 28.

Rack gear elements 82, 84, similar to the rack gear elements 62 and 64,respectively, are coupled to the side of elements 74 and 76,respectively, which face away from top plate 14. The rack gear elements82, 84 are so dimensioned and disposed that part of the rack gearelements 82 and 84, respectively, are adjacent to the slots 30 and 32,respectively, at all times during operation of the tongs.

Jaw elements 86, 88 are secured to the base parts 70, 72 respectively ofthe jaw assemblies 66, 68. The jaws '54, 86 and 56, 88, respectively,face each other.

A pinion gear 90 or 92 is disposed between and engages the teeth of therack gears 62, 82 and 64, 84, respectively. A shaft 94, 96 extendsthrough and is coupled to the gear 90 or 92, respectively.

Elongated linkage arms 98, 100 are each fixedly coupled to an end of theshaft 96. Similar linkage elements (only element 102 is visible in FIGS.1 and 2) are fixedly coupled to the shaft 94. The linkage elements abovereferred to are disposed outside of the frame 12.

An additional pair of elongated linkage elements 104, 106 (in FIG. 3)are pivot-ally coupled to the linkage elements 100, 98 respectively.Similar elongated linkage elements are pivotally coupled with respect tothe shaft 94 in a similar manner.

The linkage elements 104, 106 and their corresponding parts on the otherside are all joined together at one end by the coupling pin 110.

A holding element 112 pivotally coupled to the frame 12, is adaped toengage the coupling pin 110 when the jaws of the tongs are open, thusholding the jaws in the open position as the tongs are moved.

The tongs are adapted to be moved by cable means coupled to the tongsthrough the grab hook 114, for example.

In operation, as shown in FIG. 1, the tongs are moved over the coil 116to be lifted. With the jaws in position, the holding element 112 istie-coupled, and the tongs raised by means of the grab hook 114.

As the grab hook 114 is lifted, the links 104, 106 (shown in FIGS. 1 and2) are raised, also raising the links 100, 102 which are fixedly coupledto the pinion gears 92, 90, respectively.

Movement of the links 100, 102 also moves the pinion gears 96, 94,causing movement of the freely movable rack gears which are coupled tothe jaw assemblies 46, 48 and 66, 68.

Each rack gear moves (moving the jaw assembly of which it is a part)until its jaw meets resistance (by contacting the coil 116), then onlythe other rack gear which is coupled to that particular pinion gearmoves. When both jaws contact the coil to be lifted, further rotationonly tightens the jaws against the coil. All of the jaw assembliesoperate in the same manner.

The length of the slots 22, 24, 26, 28, 30, 32 34, and

3 36 prevents excessive movement of any of the components of the tongs.A spring 118, coupled between the jaw assemblies 46 and 48, although notessential to the invention, is-helpful in moving the jaws apart as thecoils are to be released.

Because all four jaws of the tongs are independently coupled to thepinion gears 90 or 92, the pressure applied by the jaws is equalized.

Further, because the diameter of the pinion gears 90, 92 is relativelylarge, a relatively small amount of movement of the linkage elements100, 102 results in very substantial movement of the jaws of the tongs.Because of this, the tongs may be operated where low headroom above thecoils 116 exists.

What is claimed is:

1. Coil tong apparatus comprising a hollow rigid frame having plate-likeside walls, a top plate and a bottom plate, said side walls having anarray of similarly disposed and aligned slots near said bottom plate, apair of aligned slots near said top plate, and a pair of slots disposedin the central part of each said side walls, two pairs of jawassemblies, each jaw assembly including an L- shaped member having abase part and a leg part, said base part of each member extending belowsaid bottom plate andhaving a jaw affixed thereto, the leg part of oneL-shaped member of one pair of jaw assemblies extending adjacent to saidbottom plate, roller means coupled be.- tween said leg parts adjacent tosaid bottom plate and adjacent slots in said array of slots which arenear said bottom plate, the leg part of each of the L-shaped members ofthe other pair of jaw assemblies being disposed adjacent to said topplate, roller means coupled between each of said leg parts of theL-shaped members which are disposed adjacent to said top plate and saidaligned slots which are near said top plate, four rack gear elements,one rack gear element being fixedly secured to the leg part of arespective L-shaped member with said gear elements of one pair of jawassemblies facing the gear elements of the other pair of jaw assemblies,a pair of pinion gears, said pinion gears each being fixedly coupledonto a shaft and also coupled to the rack gear elements of two jawassemblies which are facing each other,

said shafts each extending through said centrally disposed slots in saidside walls, and means coupled to each of said shafts for rotating saidpinion gears.

2. Apparatus in accordance with claim 1, wherein said means for rotatingsaid pinion gears comprises a pair of rigid lever arms each fixedlycoupled to one of said shafts and each coupled to a common forceapplication means.

3. Apparatus in accordance with claim 1, wherein d tachable means areprovided for maintaining said lever arms in a fixed position.

References Cited by the Examiner UNITED STATES PATENTS 2,337,178 12/1943Breslav 294-86 3,172,694 3/1965 Bradley 294-93 MARVIN A. CHAMPION,Primary Examiner.

G. F. ABRAHAM, Assistant Examiner.

1. COIL TONG APPARATUS COMPRISING A HOLLOW RIGID FRAME HAVING PLATE-LIKESIDE WALLS, A TOP PLATE AND A BOTTOM PLATE, SAID SIDE WALLS HAVING ANARRAY OF SIMILARLY DISPOSED AND ALIGNED SLOTS NEAR SAID BOTTOM PLATE, APAIR OF ALIGNED SLOTS NEAR SAID TOP PLATE, AND A PAIR OF SLOTS DISPOSEDIN THE CENTRAL PART OF EACH SAID SIDE WALLS, TWO PAIRS OF JAWASSEMBLIES, EACH JAW ASSEMBLY INCLUDING AN LSHAPED MEMBER HAVING A BASEPART AND A LEG PART, SAID BASE PART OF EACH MEMBER EXENDING BELOW SAIDBOTTOM PLATE AND HAVING A JAW AFFIXED THERETO, THE LEG PART OF ONEL-SHAPED MEMBER OF ONE PAIR OF JAW ASSEMBLIES EXTENDING ADJACENT TO SAIDBOTTOM PLATE, ROLLER MEANS COUPLED BETWEEN SAID LEG PARTS ADJACENT TOSAID BOTTOM PLATE AND ADJACENT SLOTS IN SAID ARRAY OF SLOTS WHICH ARENEAR SAID BOTTOM PLATE, THE LEG PART OF EACH OF THE L-SHAPED MEMBERS OFTHE OTHER PAIR OF JAW ASSEMBLIES BEING DISPOSED ADJACENT TO SAID TOPPLATE, ROLLER MEANS COUPLED BETWEEN EACH OF SAID LEG PARTS OF THEL-SHAPED MEMBERS WHICH ARE DISPOSED ADJACENT TO SAID TOP PLATE AND SAIDALIGNED SLOTS WHCIH ARE NEAR SAID TOP PLATE, FOUR RACK GEAR ELEMENTS,ONE RACK GEAR ELEMENT BEING FIXEDLY SECURED TO THE LEG PART OF ARESPECTIVE L-SHPAED MEMBER WITH SAID GEAR ELEMENTS OF ONE PAIR OF JAWASSEMBLIES FACING THE GEAR ELEMENTS OF THE OTHER PAIR OF JAW ASSEMBLIES,A PAIR OF PINION GEARS, SAID PINION GEARS EACH BEING FIXEDLY COUPLEDONTO A SHAFT AND ALSO COUPLED TO THE RACK GEAR ELEMENTS OF TWO JAWASSEMBLIES WHICH ARE FACING EACH OTHER, SAID SHAFTS EACH EXTENDINGTHROUGH SAID CENTRALLY DISPOSED SLOTS IN SAID WALLS, AND MEANS COUPLEDTO EACH OF SAID SHAFTS FOR ROTATING SAID PINION GEARS.